Method and apparatus for closing paper containers



Sept- 30, 1941- G. MEYER-JAGENBERG I 2,257,243

METHOD AND APPARATS FOR CLOSING PAPER CONTAINERS Filed May 17, 1959 l /l/H/ 'I' n 70 lll lll/l N 74 15v Fg.2 77

W//% 'Nl lt f Patented sept. 3o, 19414 METHOD AND APPARATUS Fon CLOSING PAPER CONTAINERS Gnther Meyer-Jagenberg, Dusseldorf, Germany Application May 17, 1939, Serial No. 274,303 In Germany May 23, `1938 Claims.

The invention relates to a method and an apparatus for closing paper containers and relates in addition to the container itself.

It is known to fold flatlyy together they mouthpiece of paper containers and to secure this flat closing fold by a sealing strip of metal plate pressed thereon. The use of such a sealing strip of metal plate caused additional expense which is of appreciable importance as compared with the small cost of the paper container itself; consequently, experts hav'e sought to save the use of such sealing strips.

The mouth of paper containers parafiined or impregnated in a similar manner have already been folded flat and the separate sheets or lay- .ers of paper in this iiat closing fold have been stuck together by the simultaneous use of pressure and heat, by means of the parafiin or other impregnation agent. In this, the upper end of such a fiat closing fold has already been turned over against the part located below it, and stuck on to this in suitable manner. Though the results attained in this manner were not bad, the produced closing has been found not strong enough. It, therefore, is the aim of the invention to produce a stronger closing without using a metallic sealing strip.

In the closing of paper containers in Which the container mouth is folded together flatly, according to the invention, the upper end of the fiat closing fold is bent over at right angles and pressed together transversely to the axis way, where the container mouth is folded flat and the upper end of this flat closing fold is turned over against the lower part; in this the closingy method according to the invention is carried out by the upper part of the flange created by the folding and bending over being bent at right angles and pressed together perpendicularly to the axis of the container, whilst the lower part of the flat flange is held firmly together by forces acting in parallel to the pressure of compression. The closure formed in this way in accordance with the invention has therefore at the upper part of the fiat flange created by folding and turning over, a reinforcing rib bent at right angles, in which the separate layers of paper are connected together i-n known manner by the impregnation agent or the like. Great strength is in particular attained by the reinforcing rib being thicker than the part located underneath this, of the flat ange formed by folding and bending over. The eiect which the parain or other impregnation agent sealing the individual layers of the paper together, p

exerts in the folded closure, can also be attained by a binding agent only applied on to the upper rim of the container and which develops a binding force under the influence of pressure and/or heat.

According to a further development of the invention, there is used for carrying out the process according to the invention an apparatus in which is arranged above twopress jaws known per se which in known manner hold togetherthe lower part of the fiat ange formed from the upper part of the container wall, a compression tool movable parallel to these press jaws, that is, approximately perpendicularly to the axis of the paper vessel. These tools can be provided in known manner with a heating `device `in order that the impregnation agent or the like may develop a .better binding energy by heating. With the arrangement according to the invention therefore, the direction of effort of the compression tool which compressed together the upper part bent at right angles tothe flat closing fold, is parallel to the direction of pressure of the press jaws which compress the part situated below the flat closing fold. This prevents the working of the press jaws holding together the lower part of the at closing fold being affected prejudicially by the action of the compression tool or even the-compressed part of the fiat closing fold being forced between the press jaws holding together the lower part of the at closing fold or even being forced along between these. Such inconveniences are in particular avoided furthermore according to the invention by the Working surface of the compression tool and/or the wall turned towards this surf-ace, of the press die allocated to the compression or stamping tool being arranged to rise steeply upward. 'I'he result is attained by this arrangement that on the clenching together the reinforcing rib vto be formed is somewhat pressed upwardly; this pre- `vents the clenching pressure acting indirectly downwards and affecting the working of the press jaws arranged underneath the compression or clenching tool.

It is finally a feature of the invention that one of the two said press jaws known per se is provided with a projecting clip for the bending over at right angles of the part of the flat closing fold to be later on clenched together.

Below are described by way of example the A the paper vessel.

Figure 1 is a sectional View of the apparatus, the folded closure of the container being in initial form and the parts of the apparatus in inopera-` tive position.

Figure 2 is a similar view showing the parts of l the apparatus' following the first operation and a l corresponding continuation of the container cloz sure.

Figure 3 is a similar View showing the parts of the apparatus in final position and the closure of the container in final form.

The closure hereafter described can, however, be used with any paper container, the mouth f which can be folded flat together. The upper edge of this flat part is placed together and then turned over as a part-length return fold as shown by Figure 1. This partof the fold is carried out in any desired or appropriate way, the details of .whichform` no 'part of the present invention. The paper container therefore now shows a flat flange over at right angles, which is shown by Figure 2. The part f bent over at right angles is then compressed or clenched together in a direction perpendicular to so that a reinforcing` rib V is formed. The thickness D of .thisreinforcing rib is greater than. the thickness d of the unaltered part of the flat flange F remaining underneath the reinforcing rib.y r The lateral surfaces a and b ofthe reinforcing ribV: are so arranged that they spread out obliquely upwards.r In consequence of this arrangement of the lateral surfaces of the reinforcing: rib V, this can easily be gripped and held bythe -hand Ain the delivery and distribution of The said 4arrangement of the lateral surfaces a and bj in particular prevents the reinforcing rib used,` as carrier, slipping out of the hand. Y

For the production of the closure, the development of which is illustrated by the successive operations, the tools as shown .in Figures 1-3 such tools being particularly suitable. These tools consist of a iixedly arranged press jaw I0 and a movable press jaw II, which is arranged in a horizontally reciprocating slide I2. The press jaw II is in a recess of the slide or carriage I2'and is movable arranged with respect to this slide. The press jaw II is under the iniluence of a spring I3 which forces the press jaw II out of the recess of the slide I2. The outward movement of lthe press jaw I2 is, however, limited by the bolt I4 and the nuts I5 fitted on this bolt I4. There is provided above the press jaw II in the slide I2 a recess which is limited in the horizontal direction by the inclined surface zr. 'Directly over the fixed press jaw I0 is the compressing or clenching tool I6 movable in the horizontal direction, and the front working surface y of which ls arranged obllquely.

The paper container to be closed and the upper part of which is in the folded condition shown by Figure 1, is placed between these tools, as shown by Figure 1. The slide I2 carrying the press jaw II is then moved towards the stationary press jaw I0. During this movement, the press jaw I I forces the at flange F of the vessel against the press jaw I0. During the further movement forward of the slide or carriage I2, the spring I3 is compressed, so that finally the lower part of the flange F ls firmly held between the F formed by folding over. The upper part fof this flat flange F is then bent y the axis of the paper contalner,`

press jaws II) and II. On the forward movement of the sliding carriage I2 the part f of the flat flange F projecting above the press jaws is turned over at right angles by the projecting edge z of the carriage. The clenching tool vII is now moved forward. The front end of this clenching tool I6 presses the turned-over part f of the fiat flange F into the recess which is underneath the edge a and-'which is limited atf its rear by the surface which recess at the same time' lacts as a press die. By the pressure of the clenching tool containers, wherein the walls of such open f movement in one' direction,

I6, the part f 0f the paper container is clenched together and pressed into a reinforcing rib. The tools I I, I2, I6 then return into their initial position so that the working cycle of the said tools can commence afresh on another paper container.

When paraflined paper containers are to be closed, it is advisable to provide the tools with any conventional serviceable heating device such as electric heating bodies mounted therein. It is advisable not to heat the tools over the melting point of the paraffin. If the rpaper vessels are saturated with a paraffin, the melting temperature of which lies between and 60, a heating of the tools to 30 or 40 has been found particularly advantageous.

From the foregoing. it it obvious that the invention is not to be restricted to the exact embodiment shown in the drawing but is broad enough to cover all structures coming within the scope of the annexed claims. f

I claim:

1. A method of sealing the open end of a paper container where the walls of such open end are united and formed in a part-length return bend consisting in forming the return `bend laterally, and exerting endwise end of the lateral portion while confining such lateral portion against vertical displacement in either direction.

2. A method for sealing the open ends of paper containers, wherein the walls 4of such open ends Aare brought together and formed in a partlength return bend consisting in forming a portion of the return bend into a lateral extension, confining the lateral extension' against vertical movement in eitherl direction and longitudinal and exerting longitudinal pressure upon the lateral extension in the opposite direction to l materially decrease the length of the lateral extension.

3. A method for sealingthe open ends of paper ends are brought together and formed in a part-length return bend consisting in forming a portion of the return bend into'a lateral extension, conningvv the lateral extension againstvertical movement in either direction and longitudinal move- (3o/ment in one direction, and exerting longitudinal pressure upon the lateral extension in the opposite direction to `materially decrease the length of the lateral extension, the longitudinal compression of the lateral extension forming the respectlve side edges ythereof at opposing inclinarecess corresponding to the thickness of the return bend, press jaws movable to embrace the return bend and move the same into the recess to form a lateral extension in such return bend,

pressure upon the free' l and clenching tool movable against the free end of the lateral extension to compress the same between the upper wall of the recess in the member and the upper surfaces of the press Jaws.

5. Apparatus for the sealing of paraflined or s'imilarly impregnated paper containers in which the upper end of the vessel walls is folded fiat together and the upper edge of this at closing fold is turned over against the lower part; said apparatus being provided with two press jaws, which hold together the lower part of the flat flange formed from the upper end of the vessel walls, and a compressing or clenching tool movable parallel to the direction of pressure of the said press jaws and approximately perpendicular to the axis of the paper container; one of the said two press jaws being connected with a projecting strip for the bending over at right angles of vthe upper part of the said flat flange during operation of the press jaws.

6. Apparatus for the sealing of paraiiined or similarly impregnated paper containers in which the upper end of the Vessel walls is folded fiat together and the upper edge of this flat closing fold is turned over against the lower part; said apparatus being provided with two press jaws, which hold together the lower part of the flat iiange formed from the upper end of the vessel walls, and a compressing or clenching tool movable parallel to the direction of pressure of the said press jaws and approximately perpendicular to the axis oi the paper container, the working surface of the clenching tool and the edge turned towards this surface of the press die allocated to the clenching tool, being arranged at a steep upward angle.

7. Apparatus for the sealing of paraiined or similarly impregnated paper containers in which the upper end of the vessel Walls is folded fiat together and the upper edge of this dat closing fold is turned over against the lower part; said apparatus being provided with two press jaws, which hold together the lower part of the flat flange formed from the upper end of the vessel walls, and a compressing or clenching tool movable parallel to the direction of pressure of the said press jaws and approximately perpendicular to the axis of the paper container; one of the said two press jaws being connected with a projecting strip for the bending over at right angles of the upper part of the said fiat flange; the working surface of the clenching tool and the edge turned towards this surface of the press die allocated to the clenching tool, being arranged at a steep upward angle.

8. An apparatus for sealing the open ends of paper containers wherein the walls of such open ends are brought together and formed in a return bend, said apparatus comprising a member formed with a recess, press Jaws operating on the return bend of the closure to force the same into the recess of the member to thereby form a lateral extension in said return bend, the vertical spread of which is confined by the wall of the recess and one of the press jaws, and a clenching member movable against the free end of the lateral extension of the return bend and forcing the same into the recess to reduce the longitudinal length of the lateral extension, the press jaws and recess in the member confining the lateral extension against substantially Vertical spreading during the operation of the clenching member, the press jaws serving to prevent displacement of the contacting walls of the closure below the lateral extension.

9. A construction as defined in claim 8, wherein the opposing faces between which the lateral extension is subjected to endwise pressure are opposltely inclined.

10. A construction as deiined in claim 8 wherein the end wall of the recess in the member and the operative face of the clenching member are inclined upwardly and outwardly relative to the axial line of the container.

GNTHER rviEYER-JAGENBERG. 

